Conversion factors

Conversion factors between cubic metres and green tonnes

A revised set of factors that indicates the volume of standing tree crop (wood raw material equivalent - wrme) needed to produce one unit of a final product was published in FC Technical Paper 19 Revised Forecasts of the Supply and Demand for Wood in the UK. The factor for paper products includes an allowance for the proportion of recycled paper manufactured in the United Kingdom. The factors are shown below.

Wood product conversion factors to wrme (standing volume)

Product

Measurement Unit

Factor to WRME

Fuelwood and charcoal

m³

1.25

Other industrial roundwood

m³

1.25

Softwood sawnwood

m³

2.13

Hardwood sawnwood

m³

2.09

Newsprint

tonnes

4.30

Printing and writing paper

tonnes

4.30

Other paper and paperboard

tonnes

4.30

Plywood

m³

3.67

Fibreboard

m³

2.35

Particleboard

m³

1.61

Veneer sheets

m³

3.67

The charcoal conversion factor is for volume to volume. About 7.8m3of wood is required to make one tonne of charcoal, but one tonne of charcoal is equal to about 6m3in volume.

The conversion factor for oriented strand board (OSB) is higher than for other types of particleboard, and the average for particleboard has been constructed by assuming that OSB is 25% of the total.

These factors were not used for Tables 3.1 and 3.3, which used an older set of factors to convert to wrme underbark.